Sensitivity Analysis of Load Distribution in Light-Framed Wood Roof System due to Typical Modeling Parameters

Since failure of roof systems in past high wind events have demonstrated the consequences of not maintaining a continuous load path from the roof to the foundation, many studies have been conducted to better understand this load path, including how loads are distributed in the system. The present study looks to add to the current knowledge of the vertical load path by focusing on uplift loads and by considering the sensitivity of different modeling parameters. This is done by developing and assessing load influence coefficients for various roof-to-wall (RTW) connections. An analytical model of a light-framed wood structure using finite element software is developed. The model has a gable roof system comprised of fink trusses and is modeled in a highly detailed fashion including the explicit modeling of each connector/nail in the system. The influence coefficient plots indicate that the distribution of loads is indeed sensitive to the overall stiffness of RTW connections but is not overly sensitive to their relative stiffnesses. This was investigated by looking at cases where all connections have the same stiffness and cases where they can have different stiffnesses. However, the relative stiffness begins to have a larger impact as they begin to soften due to yielding. Furthermore, the stiffness of the sheathing connectors did not appear to have much of an impact on the distribution of load but the sheathing stiffness itself did have a notable impact

Macrobenthic Communities in the Northern Gulf of Mexico Hypoxic Zone: Testing the Pearson-Rosenberg Model

The Pearson and Rosenberg (P-R) conceptual model of macrobenthic succession was used to assess the impact of hypoxia (dissolved oxygen [DO] ≤ 2 mg/L) on the macrobenthic community on the continental shelf of northern Gulf of Mexico for the first time. The model uses a stress-response relationship between environmental parameters and the macrobenthic community to determine the ecological condition of the benthic habitat. The ecological significance of dissolved oxygen in a benthic habitat is well understood. In addition, the annual recurrence of bottom-water hypoxia on the Louisiana/Texas shelf during summer months is well documented. The P-R model illustrates the decreasing impact of organic enrichment on the macrobenthic community distally from the source. To test the underlying principles of the P-R model using bottom-water concentration of dissolved oxygen as a proxy for distance from the source of organic enrichment, four sites were chosen based on the frequency of hypoxia occurrence in the hypoxic zone of the northern Gulf of Mexico. The chosen sites were arrayed from west to east on the Louisiana continental shelf, where site A was farthest from the Mississippi River and least impacted by seasonal hypoxia with75% annual exposure time. Site C was impacted by seasonal hypoxia between 25% and 50% of the time. Site B was impacted by seasonal hypoxia between 50% and 75% of the time. Sites B and C were situated near the vicinity of the Atchafalaya River between sites A and D. To measure the spatio-temporal effect of hypoxia on the macrobenthic community, samples were collected during early spring (April 2009), late summer (September 2009), and mid-summer (August 2010). Results indicated that the macrobenthos collected during mid-summer were the most stressed community, with the exception of site C. The cumulative effect of annual hypoxia on the macrobenthos at each site was apparent from the species diversity, abundance, and biomass. High values of species diversity, richness and evenness at site A and low values at site D indicated the existence of a westward-diminishing hypoxic gradient on the Louisiana/Texas shelf interrupted by the Atchafalaya River discharge. Assessment of successional stages of the benthic communities of the four sites with the multivariate analyses of nonmetric multi-dimensional scaling and principal component analysis identified the spatial gradient of hypoxia. Examination of the macrobenthos and available environmental data with canonical correspondence analysis indicated that sedimentary organic carbon, as well as bottom-water dissolved oxygen, had a strong impact on the benthic community structure. The study successfully demonstrated the applicability of the Pearson-Rosenberg model on the Louisiana/Texas continental shelf and the results were consistent with the predictions of the model. Site A was in the advanced phase of stage II succession; whereas sites B and C were in the intermediate phase of stage II succession, and site D was in the intermediate phase of stage I succession in the Pearson-Rosenberg successional continuum

Real-time physiological identification using incremental learning and semi-supervised learning

The widespread usage of wearable sensors such as smart watches provide access to valuable objective physiological (such as Electrocardiogram(ECG)) signals ubiquitously. Healthcare domain has been tremendously benefited by the collection of physiological signals which can be used for health monitoring of patients. The signals from the wearable sensors enabled the researchers and data experts to process them and identify the human physiological state by classifying the human activities. This led to the growth and development of smart ecosystem in the healthcare domain.In this thesis, ECG signals have been investigated as the physiological measure to detect human activities. Various measures are extracted from ECG, such as heart rate variability, average heart rate etc. and their relationships with different human activities are investigated. To build a comprehensive analytical machine learning model for ECG signals and to enable the continuous monitoring of humans, one would need access to real time streaming of continuous data. So, the data would be unsupervised most of the time and it would be very expensive (almost practically impossible) to label all the data streaming in real time. Also, it is highly probable that the data is collected from different sessions and varying situations. Therefore, the machine learning models need to be able to adapt to new sessions. This would be a major challenge in human state monitoring provided that the conventional predictive models work only on the stationary data. Also, these models would fail to work on the data from multiple sessions. To provide a practical solution to address above issues, two advanced methods in machine learning have been discussed in this research: Incremental learning and Semi supervised learning. Incremental learning is a paradigm in Machine learning where the stream of input data is continuously used to extend the existing knowledge learnt by the model. The incremental learning module has been built in Apache Spark platform which provides a scalable cloud infrastructure to apply machine learning algorithms on streaming data. Semi supervised learning is another solution implemented in this thesis where some out of all the data points are labelled. Different semi supervised algorithms have been studied and applied which learn the relationship between features and adapts the model to data from multiple sessions. Finally, the results are compared and the implementation ideas for the discussed solutions have been proposed.Master of ScienceComputer and Information Science, College of Engineering & Computer ScienceUniversity of Michigan-Dearbornhttps://deepblue.lib.umich.edu/bitstream/2027.42/143516/1/49698122_Thesis_Shashank_Shivarudrappa.pdfDescription of 49698122_Thesis_Shashank_Shivarudrappa.pdf : Thesi

Etiology and Management of Sexual Dysfunction

Sexual dysfunction is the impairment or disruption of any of the three phases of normal sexual functioning, including loss of libido, impairment of physiological arousal and loss, delay or alteration of orgasm. Each one of these can be affected by an orchestra of factors like senility, medical and surgical illnesses, medications and drugs of abuse. Non-pharmacological therapy is the main stay in the treatment of sexual dysfunction and drugs are used as adjuncts for a quicker and better result. Management in many of the cases depends on the primary cause. Here is a review of the major etiological factors of sexual dysfunction and its managemen

Lutein and zeaxanthin attenuates VEGF-induced neovascularisation in human retinal microvascular endothelial cells through a Nox4-dependent pathway

Age-related macular degeneration (AMD) and proliferative diabetic retinopathy (DR) are two of the most common and severe causes of vision loss in the population. Both conditions are associated with excessive levels of vascular endothelial growth factor (VEGF) in the eye which results in an increase in the formation of new blood vessels through a process called neovascularisation. As such, anti-VEGF therapies are currently utilised as a treatment for patients with AMD however they are associated with painful administration of injections and potential degeneration of healthy endothelium. There is therefore growing interest in alternate treatment options to reduce neovascularisation in the eye. The use of carotenoids, lutein (L) and zeaxanthin (Z), has been shown to improve vision loss parameters in patients with AMD, however the underlying mechanisms are not well-understood. We studied the impact of these compounds on neovascularisation processes using an in vitro cell model of the retinal microvascular endothelium. Our findings show that L and Z reduced VEGF-induced tube formation whilst, in combination (5:1 ratio), the compounds significantly blocked VEGF-induced neovascularisation. The carotenoids, individually and in combination, reduced VEGF-induced oxidative stress concomitant with increased activity of the NADPH oxidase, Nox4. We further demonstrated that the Nox4 inhibitor, GLX7013114, attenuated the protective effect of L and Z. Taken together, these findings indicate the protective effect of the carotenoids, L and Z, in reducing VEGF-mediated neovascularisation via a Nox4-dependent pathway. These studies implicate the potential for these compounds to be used as a therapeutic approach for patients suffering from AMD and proliferative DR

Macrobenthos Community Succession In the Northern Gulf of Mexico Hypoxic Regions: Testing the Pearson-Rosenberg Model

The Pearson and Rosenberg (P-R) conceptual model of macrobenthic succession was used to assess the impact of hypoxia (dissolved oxygen concentration ≤2 mg L–1) on the macrobenthic community on the continental shelf of the northern Gulf of Mexico. The stress-response relationship between bottom-water oxygen concentration and the macrobenthic community was used to determine the ecological condition of the benthic habitat. In lieu of testing the effect of decreasing influence of organic enrichment on the macrobenthic community as a function of distance from the source of organic pollution, we tested the effect of bottom-water dissolved oxygen concentration as a proxy for distance from the source. To include the seasonal response in the long-term cumulative effect of recurring hypoxia on the macrobenthic community, samples were collected during early spring (April 2009), late summer (September 2009), and midsummer (August 2010). The cumulative effect of annual hypoxia on the macrobenthos at each site was apparent from the species diversity, abundance, and biomass. High diversity values at site H7 and low diversity values at site A6 indicated the existence of a westward-diminishing hypoxic gradient on the Louisiana/Texas shelf, interrupted by the Atchafalaya River discharge. Unsurprisingly, the macrobenthos collected during midsummer were generally the most stressed community, with the exception of site E4. Assessment of successional stages of the benthic communities of the four sites with multivariate analyses of nonmetric multidimensional scaling, distance-based redundancy analysis, and principal component analysis identified the influence of bottom-water hypoxia. The study demonstrated the applicability of the P-R model in predicting successional change in the macrobenthic community on the Louisiana continental shelf. Site H7 was in the advanced phase of stage II, sites E4 and D5 were in the intermediate phase of stage II, and site A6 was in the intermediate phase of stage I in the P-R successional continuum

Vertical Distribution of Macrobenthos in Hypoxia-Affected Sediments of the Northern Gulf of Mexico: Applying Functional Metrics

Continuing trends of declining bottom-water dissolved oxygen (BWDO) in coastal oceans are a threat to marine organisms, especially the benthos, and in the northern Gulf of Mexico (nGOM), the hypoxic area is expected to expand. Within-sediment vertical functional metric responses of macrobenthos were examined in four depth strata at four sites with different histories of exposure to seasonal hypoxia. The sites H7, D5, E4, and A6 between 30 and 39-m water depth represented a historical oxygen stress gradient from 5.4 to 2.1 mg L−1 BWDO (mid-summer 11-year mean), from which macrobenthos were sampled in spring and late summer 2009 and in mid-summer in 2010. High abundance together with high biomass and production potential within upper strata under low BWDO stress supports the primacy of a numerically driven response in this system. Total abundance decreased along the BWDO stress gradient, and the lowest abundance coincided at the highest stress (MaxStress) site together with the highest proportion of opportunists, the smallest mean size, and the shortest turnover time. Accordingly, the relative abundance of opportunists within the upper two strata increased while surface deposit feeders decreased with greater hypoxic stress. Notwithstanding the proportion of opportunists, functional metrics generally decreased across the BWDO stress gradient within the upper strata, and metrics generally varied inversely between upper and lower strata. The findings underscore how vertical benthos distribution patterns reflect the BWDO exposure regime and how secondary production varies as an indicator of trophic transfer potential and organic matter processing within this system

Sarcomatoid salivary duct carcinoma of minor salivary gland: A rare case

A 35-year-old female presented with swelling in the soft palate. Fine needle aspiration cytology (FNAC) revealed pleomorphic adenoma, and on histopathological examination, it was diagnosed as carcinosarcoma/salivary duct carcinoma in the minor salivary gland, which was confirmed by immunohistochemical stains. We report this case for its rarity